A semiconductor light-emitting device such as a light-emitting diode (LED) or a laser diode (LD) uses an electroluminescence phenomenon, i.e., a phenomenon of emitting light from a material through an application of a current or a voltage. As electrons are combined with holes in an active layer of the semiconductor light-emitting device, energy corresponding to an energy band gap of the active layer may be emitted as light. Therefore, a wavelength of light generated by the semiconductor light-emitting device may vary according to a size of the energy band gap of the active layer.